Mediterranean Diet and the Metabolic Syndrome: The End of the Beginning

The metabolic syndrome is now both a public health and a clinical problem. The most recent estimates from the National Health and Nutrition Examination Survey (NHANES) 2003-2006 reported that approximately 34% of adults in the United States have the metabolic syndrome. The relationship between adherence to a Mediterranean diet and the prevalence of metabolic syndrome has been explored in cross-sectional studies with discordant results. Two prospective studies with a follow up of 6 and 7.5 years show that subjects with the highest adherence to a Mediterranean diet had lower cumulative incidence of metabolic syndrome than those with the lowest adherence. Two interventional trials document a positive effect of a Mediterranean diet on reversal of metabolic syndrome. The Mediterranean diet may be also useful to ameliorate liver function tests in obese patients with insulin resistance and diabetes. There is no consensus as to what diet is the optimal one for patients who have the metabolic syndrome. A Mediterranean diet that is moderately lower in carbohydrate (45%), and moderately higher in fat (35-40%), with less than 10% of saturated fat, may be beneficial for ameliorating features of the metabolic syndrome, including effects on insulin sensitivity, blood lipids, and liver function.